Stop-motion for steam-engines and other prime movers.



' J. W. SARGBNT;

STOP MOTION FOR STEAM ENGINES AND OTHER PRIME MOVERS.

APPLIGATION FILED mum, 1909.

989,062. Patented Apr. 11,1911.

3 SHEETS-SHEET 1.

WIT NEESEB, NVENTDR. wfifiafl-- 46% fl/l W ATTURNEY J. W. SARGENT.

STOP MOTION FOR STEAM ENGINES AND OTHER PRIME MOVERS.

APPLICATION FILED JUNE 4, 1009.

WITNESSES Patented Apr. 11, 1911.

3 SHEETS-SHEET 2.

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|NVELNTE1R J. W. SARGBNT. 1

STOP MOTION FOR STEAM mamas AND OTHER PRIME movsns.

APPLIUATION FILED JUNE 4, 1909. 989,062, Patented Apr. 11, 1911.

FIEE] WITNEEEEE Y INVENTEJR ATTURNEY JOHN W. SARG-ENT, OF PROVIDENCE,RI-IODE ISLAND.

STOP-MOTION FOR STEAM-ENGINES AND OTHER PRIME MOVERS.

Specification of Letters Patent.

Application filed June 4, 1909. Serial No. 500,227.

Patented Apr. 11, 1911.

To all whom it may concern:

Be it known that 1, JOHN WV. Sanonn'r, a citizen of the United States,residing at Providence, in the State of Rhode Island,

have invented a new and useful Improvement in Stop -Mot.ions for SteamEngines and other-Prime Movers,.o:f which the fol lowing is aspecification.

The object of my invention is to provide a simple means forautomatically causing the supply of steam or other motive fluid to beshut off from the engine, when the latter is caused to run faster than acertain predetermined rate of speed. This result is attained by mountingan inertia hannner on the crosshead in such a manner that at and belowthe normal rate of speed, the hammer will move with and remain quiet inrelation to the cross head, and is kept in its normal position by theforce of gravity or the equivalent tension of a spring. But whenOVQISPGQtllIlg occurs, the inertia of the hammer is sullieient to causethe same, at one end of the stroke, to move forward from the crossheadin the direction in which it has been traveling, and as the cross-headcomes to a standstill the hammer will strike with a considerable forceto impart movement to a releasing, or other mechanism, whereby thethrottle valve is caused to close, or the valve gear to come to its zeroposition of cut oil.

In the accompanying drawings: Figure 1 is asectional side elevation ofthe outer end of the slides and crosshead ot' a horizontal engine, witha gravity stop hammer which embodies my invention, pivoted to thecrosshead. Fig. 2 is an end elevation of the same. Fig. 3 is similar toFig. 1, but shows the stop hammer in action. Fig. 4 ,shows anarrangement adapted for a vertical engine, where a spring is used tohold the stop hammer in its normal position; Fig. 5 shows the latterarrangement in action. Fig. 6 shows a hammer and sliding hammer mountedin bearings on a bracket attached to the erossbead, with a spiral springpressing directly against the hammer. Fig. 7 shows the same in action.Fig. 8 shows a stop hammer attached directly to the spring. Fig. 9 showsthe same inaction.

In each case the crosshead is shown at itsextreme outer position fromthe cylinder.

Referring now to Figs. 1, 2 and 3, which show a simple hammer pivoted tothe crosshead of a horizontal engine; A and A are the slides in theengine bed. B is the crosshead havin an arm 0 carrying a pin D on whichthe stop hammer E 1s pivoted. In the normal running of the engine thehammer rests down against the hub of the crosshead at H. The center ofgravity G of the hammer E, must be so located that at a certainpredetermined rate of speed, the inertia of the weight will overcome theaction of gravity and cause the hammer to turn forward on its pivot D.As the hammer E thus turns to strike the blow its center of gravity isesand the levcmge increases, causing more rapid action until its fullmotion is acquired. And to limit the forward movement, the hammer l)strikes against the crosshead hub at K. As an example of the existingconditions, when we have an engine of 4. feet stroke making 100revolutions per minute, the inertia of any piece on the crosshead at theend of the stroke is nearly seven times its own weight in pounds. Theinertia increases from the zero point at mid stroke so that for thisparticular engine; in order to have the stop hammer come into actionslightly before the end of the stroke, at say 105 revolutions, the ratioof the inertia leverage I, to the gyratory leverage J, would have to beabout one to eight. Before the end of the return stroke of the enginethe vibrate, and will remain quiet in relation to the crosshead. Variousmethods may be em ployed to utilize this striking movement of the stophammer to shut oil' the supply of steam to the engine, such as a latchreleasing mechanism, shown in Figs. 1; 2 and 3, where a vertical arm Lin front of the stop hammer E, is pivoted to the bed plate at N, and hasa horizontal latch arm 0, which in normal running engages with thesquare block P, projecting from the rocker Q. This rocker Q is pivotedto the bed plate at R, and at its upper end is connected by means of alink S to the throttle valve or cut off mechanism of an engine. The linkS, is strained by a weight or spring in the direction of the arrow, asshown in Fig.1., so that when the latch O, releases the block P,

has a leverage a, on the hammer, as shown the rocker Q, immediatelymoves to the position shown in Fig. 3, and the supply of steam to theengine is shut OH".

In a pivoted arrangement especially adapted to vertical engines, asshown in Figs. 4 and 5, the hammer M, is shown in the form of abellcrank lever, and is held in its normal position by means of a spring T,one end of which is pivoted to the pin V, on the crosshead, and theother end to the pin 011 an arm X of the'han'nner M. The arm X moves inaction between the stops Y and Z of the crosshead' In the normal runnirig position of the hammer, the spring T in Fig. t. But when in fullaction the leverage is at zero as shown in Fig. 5. In this arrangementthe center of gyration is at I), being much farther out from the centerline of the pivot D, than in the arrangement shown in Figs. 1, 2 and 3,so that the hammer will move quicker. It is obvious that thisarrangement is also well adapted to a horizontal engine.

Figs. (5 and 7, show a sliding stop hammer arrangement, where aspiralspring acts directly against the hammer. The spring should have a largeinitial compression in proportion to its working movement, in order toget a prompt action of the hammer. The weight 0 tightly tits the hammerd and is pinned thereto the said hammer being made to rest freely inbearings e a of the bracket f, attached tothe crosshead. The spring g incompression tits loosely in the annular spice around the hammer, and innormal running holds the weight 0 hard against the bearing a. The end ofthe hammer cZ just clears the arm L, and when the acceleration of theengine is suflicient to overcome the tension of the spring, the hammer dmoves forward, so that the weight 0 comes against the bearing a and theend of the hammer d strikes the lever L, thus causing the release of thecut-otf mechanism, The line through the bearings of the hammer'd is madeon an incline, for the purpose of relieving the bearings c c, offrictionat the instant of the hammers action. In the example of thebefore mentioned engine where the inertia is about seven times theweight of thestop hammer, in pounds, it is obvious that if the inclineis 1 in 7, the hammer will be-practically afloat. In these two views,Figs. 6 and 7, a toggle releasing mechanism is shown.

In Figs. 8 and 9 the hammer is attached at m, directly to a=flat springZ, which latter is firmly secured to the crosshead at n. A pin 0projecting from the crosshead through a slot 79 in the hammer acts as astop for the hammer i in both directions, and has a safety collar (1 atits outer end, for the purpose of holding the stop hammer to thecrosshead in case the spring should break. In normal running the springZ holds the hammer 2' against the pin 0, as shown in Fig. 8. \Vhen theacceleration is sufficient, the" end it" of the hammer i moves forwardand strikes the arm L for the release of the cut-on mechanism. At thesame time the free movement of the spring Z, causes the end OI theham'mer 2' to r as well as to move forward, until it is stoppeo at the endof the slot 71 as shown in Fig. 9. This upward movement of the heavy endof the stop hammer, gives it a greater leverage upon the spring, so thatwith a considerable initial tension in the spring, the increasingleverage of the hammer will offset the increasing tension of the springduring the striking movement. In the two views Figs. 8 and 9 a latchreleasing mechanism is shown.

I claim as my invention. v

1. In a motive engine, the combination of a reciprocating member havinga uniform travel ofaccele'rated and retarded motion, a valve-actuatingmechanism, and an inertia hammer carried by said ,reciprocating member,which hammer, upon an increase in the speed of the engine beyond acertain pre determined limit, moves automatically forward by its owninertia beyond the normal limit of its motion with'the saidreciprocating member, and strikes an independent automatic hammer blowupon a portion of the valve actuating mechanism, to cut oil the supplyof motive fluid from the engine.

2. In a motive engine, the combination of a reciprocating member havinga uniform travel of accelerated and retarded motion, an inertia hammerpivoted to said member with its center of gyration out of line with thecenter of motion and held in normal position by gravity, whereby whenthe speed of the engine exceeds a certain "predeter-- mined limit, theinertia hammer will be caused to rise and strike a hammer blowindependently of the reciprocating member, toshut off the supply-ofmotive fluid from the engine.

BENJAMIN L. DENNIS, SOGRATES SoHoLrmLn.

